<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div{
			border-radius: 50%;
			-moz-border-radius: 50%;
			-webkit-border-radius: 50%;
            width: 50px;
            height: 50px;
            background-color: #0d92e847;
            position: absolute;
            left: 100px;
            top:0;
        }
    </style>
	<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.5.1/jquery.js"></script>
</head>
<body>
    <h2>鼠标绑定小盒子</h2>
     <div id="div"></div>
     <script>	
		$(document).mousemove( function(e) {
			let div = $('div');
			$('div').css({'left': e.clientX - $('div').width()/2 + 'px', 'top': e.clientY - $('div').height()/2 + 'px'});
		})


     </script>
</body>
</html>